Day 14, Tuesday, 15 September, 2015 Vector Problems Graphical representation Resultant Addition...

21
Day 14, Tuesday, 15 September, 2015 Vector Problems Graphical representation Resultant Addition Subtraction Reference Angle Sin, Cos, Tan Pythagorean Theorem Law of Cosines Resolving Components Angle of a Resultant: tan -1 Θ Problem page 75

Transcript of Day 14, Tuesday, 15 September, 2015 Vector Problems Graphical representation Resultant Addition...

Day 14, Tuesday, 15 September, 2015Vector Problems

Graphical representation Resultant Addition Subtraction Reference Angle Sin, Cos, Tan Pythagorean Theorem Law of Cosines Resolving Components Angle of a Resultant: tan-1 Θ Problem page 75

In summary: In an equation or operation with a scalar or dot

product, the answer is a scalar quantity that is the product of two vectors.

The dot product is found by multiplying the components of vectors that are in the same direction.

ABcosΘ In an equation or operation with a vector or

cross product, the answer is a vector quantity that is the product of two vectors.

The cross product is found by multiplying the components of vectors that are perpendicular to each other.

ABsinΘ

Vocabulary

Speed is a scalar with magnitude only

Velocity is a vector with magnitude

and direction

w r t means with respect to

Lecture- Vectors Graphical representation Resultant Addition Subtraction Reference Angle Sin, Cos, Tan Pythagorean Theorem Law of Cosines Resolving Components Angle of a Resultant: tan-1 Θ Problem page 75

Graphical representation

Arrows Can slide around Cannot change direction Cannot change length Add tip to tail

Resultant

Addition

Addition of several vectors

Subtraction

Reference Angle

Always in Quadrant I

Sin, Cos, Tan

Sine = sin = opp/hyp

Cosine = cos = adj/hyp

Tangent = tan = sin/cos = opp/adj

Complimentary Angles

Complimentaryangles makeother anglesfeel goodabout themselves

Pythagorean Theorem

R2 = A2 + B2

Works only for 90º angle

Pythagorean Theorem

Law of Cosines

R2 = A2 + B2 – 2AB cos Θ

Works for any angle

Resolving Components

x = r cos Θ

y = r sin Θ

Angle of a Resultant:

tan-1 Θ

Typical Vector Problems

1. Walking home

2. Boat on a river

3. Three vectors

Chapter 3 Problems

Credits

Reference Angle www.netcomuk.co.u

Complimentary Angles Cartoon www.cartoonstock.com

Vector Addition and Subtraction Wikipedia

Credits II

Vector Sliding and Multiple Additions www.physics.uoguelph.ca

Resultant www.mathwarehouse.com